The Social Communication Questionnaire is one of the most commonly used screening tools for autism spectrum disorder. The Social Communication Questionnaire is a caregiver-reported questionnaire with 40 items based on questions from the Autism Diagnostic Interview–Revised. This study collected Social Communication Questionnaire data from a community-based, multi-stage case identification design epidemiologic study in one socioeconomically disadvantaged county in Taiwan. The Social Communication Questionnaire was distributed to 3034 school children, aged 6–8 years. Item prevalence results indicate males were reported to have more autism-related behaviors than females (higher prevalence on most items), in the whole study sample as well as in children meeting Social Communication Questionnaire clinical cut-offs (>=15). Children whose biological fathers completed the Social Communication Questionnaire were reported to have more behavioral issues than children whose biological mothers were the respondent. Lower respondent education levels were associated with reports of clinically concerning autism-related behaviors. However, males were not at higher risk of meeting Social Communication Questionnaire clinical cut-offs than females in this study population. Findings from this study help to better understand reporting patterns on children’s autism-related behaviors potentially due to social demographic characteristics and child sex, which may lead to improved identification of these behaviors.